The present invention relates to electrical feedthrough devices and particularly to a multiple-lead electrical feedthrough device for conveying signals to and from electrical components enclosed in an evacuated vessel or enclosure.
There are numerous applications where it is necessary to penetrate an evacuated enclosure with a multiplicity of electrical leads so as to provide signal access to electrical components contained therein. One such application for which the present invention has particular but not limited utility is in infrared detector assemblies. Such assemblies include a vacuum enclosure in which are contained a multiplicity of detector elements and associated circuitry and components whose signal responses must be brought out via leads or feedthroughs hermetically penetrating the enclosure to an external image reconstruction system. These feedthroughs must be extremely impervious to gas penetration so as not to jeopardize the requisite hard vacuum within the enclosure over an extended operating life. Infrared detector assemblies are often subjected to hostile environments during use which may involve extreme temperature variations and physical shock. Matching of the expansion and contraction characteristics of the materials making up the feedthrough is an important consideration if their hermetic character is to be maintained both during the manufacturing process and subsequent use of an infrared detector assembly. Should even a single feedthrough lose its imperviousness to gas penetration into the enclosure or a lead break off or become open-circuited, the detector assembly typically must be scrapped, as multiple-lead feedthroughs have not been readily replaceable.
When dealing with a multiplicity of feedthrough leads, as in the case of infrared detector assemblies, it would be highly desirable from a manufacturing standpoint to utilize automated lead welding or soldering equipment to rapidly and reliably effect the numerous electrical joints at the opposed ends of the leads to circuit elements internal and external to the vacuum enclosure. Multiple-lead vacuum feedthroughs are not currently configured such as to lend themselves to such automated lead bonding equipment.
It is accordingly an object of the present invention to provide an improved multiple-lead vacuum feedthrough.
A further object is to provide a vacuum feedthrough of the above-character, wherein the multiple leads are arranged in densely packed relation.
An additional object is to provide a vacuum feedthrough of the above-character, wherein the multiple leads are arranged in a manner readily accommodated by automated lead bonding equipment.
An additional object is to provide a vacuum feedthrough of the above-character, which is structured such as to be readily replaceable without harm to the enclosure to which it is adapted and without prejudice to its hermetic character.
Other objects of the present invention will in part be obvious and in part appear hereinafter.